Bash Completion for perl6, panda, and rakudobrew

Perl6 --
Basic support for perl6{,-m,-j,-p} commands. We only have options
listed in the help menu as of now. I will provide better support as I
learn of more options and their sytax.
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Panda --
We are currently run perl6 and search @*INC for type
'CompUnitRepo::Local::Installation', and then look for
$compunit/panda/projeccts.json, which we parse for modules. this may
change over time.
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Rakudobrew --
Support is currently minimal. future versions will try to
resolve all versions automaticly for
'rakudobrew build <backend> <version>' commands.